Continuous amalgamator



Feb. 13, 1940. H H CULMER 2,190,632

CONTINUOUS AMALGAMATOR Filed June l, 1936 3 Sheets-Sheet 1 XW QW 3 Sheets-Sheet 5 Filed June l, 1936 n Su xkbutw Patentes Feb. 13, 1940 in srre CONTINUOUS `Amm(alii/nvron Harry Culmer, Chicago, Ill., .assignorbof one-fil tenth `to Mary Susanna Miller, Chicago, l

Application June 1, 193s, serial No. saaie 1 claim. (Ci. `tos- 190) y This invention relates to anew and improvedV amalgame `so formed from their entrainingj4 gangue compound, and simultaneously removing the amalgame as rapidly as formed from the mer-` cury bath' so that the excess mercury is immedi-` ately available to take up more amalgams with- `out the intermediate necessity'of `retortingthe whole of themercury used; to` provide an improved method and means for recovering free mercury in an amalgamation process; to provide a series of 'recovery` steps in an amalgamation process for recovering tree mercury; to provide an improved apparatus for forcing "ore into a mercury bath;` to provide an apparatus wherein the mercury bath is subjected to an electrical field; and to provide an apparatus which issim ple in construction and operation, and requiring the minimum amount of attention to operate.

While it is old in the art to create amalgams, it has been extremely difficult to effect sufficient contact oi all metallic particles withthe mercury, owing, in a great degree, to the factthat flmercury in 4the presence of water forms a film over'the surface of the mercury or between the water and the mercury. Also when the ores and other nely divided metals are passed in fine or fairly coarse condition over this film, they do not have enough affinity f'orthe mercury to break through the film andinto molecular refarrangement 4freely enough to give the mercury opporf tunity to take them up, and this results in a decided drop in the eiiciency of the known methods; andresults in some of the metals passing from the amalgamating table out into the tailings.

" Especially is this true when the process of combining the metals with the mercury is to be accomplished in andfrom a continuous stream of flowing water, as has been heretofore desirable, and the means in common practice.

I am aware of methods of batch treatment where` the mercury and divided metals and ores are shaken together in barrel mixers and mills .that result in great loss of mercuryby breaking it up into iine globules and losing it in the tailings. Finely divided mercury knownin the art as flour .of mercury, requires laborious .treatment i mercury;

` the wet amalgamating process. g

bath into a front compartment I4,

of the mercury bath plates and the like the outlet pipe washer `2.1". f water for the washer4 23 of thetailings to 'elect therecovery of such ,lost and in :most y,cases this mercury is abandonedinfthe'tailings of the millywhich is a costly Practice. i? i v `An illustrative embodiment `of my .invention is '.shownin the accompanying drawings, in which s sATENif-'yoFHC-E= yFigure 1 is a view of theamalgamating system with portions'shownl in section.

' Fig. 2 is a cross sectional-view of the amalgam concentrator. i l L 1 l Fig. 3 is a cross sectional view ofthe amalgam :lter press showing the piston at'theA upper portion'lof the cylinder. 1 'e l v Fig. 4` is a `crosssectionallview `of thecentrif bath. f.

Fig, 5 is a cross sectionalview of the mercury bath taken on line 5``5 of Fig."1.

Fig. 6 yis a diagrammatic layout or flow sheet of I Fig. 7 is a diagrammatic layout or of the dry amalgamating process.

The apparatus containing my amalgamatng4 systemcomprises 'a centrifugal pump I connected by shaft 2 to an electric motor 3, which is mounted on a base 4. A receiving hopper 5 communicates with the central intake f the pump `I, into which ore 6 is fed bymeans of a'ltraveling belt 1 which is. driven by a drum 8 through drive belt il4 by a driving means, not; shown. i Y

" Pipes I0 provide the water supplyorushing the ore E; A mercury bath I2 is located atjthe base of the pump I, below'the blades II, and is provided with a partition` Itfor dividing 'the and a back compartment I5, as shown in'Fig'. 5. l

A mercury `inlet pipe I1 is connected at lone end to the side walls 'in front compartment Il I 2`, and one end'of the' out-2 let pipe I8 is connected to theside wallsfofthe back compartment lof the mercurybath I2.

- The other end of the Amercury inlet vpipeITis bent IS whichishoused in a conin the form of a coil i taine:v 20 and is surroundediby solenoid 2| hav-i ing lead wires 224-22` which lare connected to a source of current, not shown'. The other end` of I8 is connected toan amalgam washer 23, through a valve "or, stop cock 24. Three separating baffles 25, and threeconcentrating baffles 26 are symmetrically housed within the Water pipe 21` provides` the wash and is provided with a valve 28. The washer 23 is also provided .with an outlet pipe 29 through` which the water is drained oi.4 Aiorccpump 30 is connected to ugalamalgamating pump and attached mercury .15

l the cylinder 6,5.

3l having a valve 32.

The force pump 30 is connected to the amalgam concentrator 34 through pipe 33. The bottom cap 35 of the concentrator 34 is provided with an aperture into which a plug 36 having a central passageway37 is threaded. A stack of circular lter discs 39 is secured to the plug 36 andthe discs 39 are provided with a central opening registering with the passageway 31. The discs 39 are held in place on the plug 36 by bolts 40, which are threaded through the solid cover plate 4|. A cylinder 42 surrounds the stack of filter discs 39 and is held in place in the concentrator bythe' sloping annular shelf and guide 43. Valve` 44 and check valve 45 are connected to rthe return pipe 46 which is connected at one end to thev passageway 31 and at the other end to the mercury inlet pipe l'l. The concentrator 34 is also provided with` an air pressure system, not shown. Air under Ipressure is .delivered .through an air inlet pipe541 :with an attached air. pressure indicator 48flinto the ,-concentrator34. The air in the concentrator may be released through the outlet pipe-49-havinga valve 50, in the event that the air'pre'ssure inthe concentrator becomestooA great. The bottom cap 35 of the concentrator 34 is also provided with anoutlet 5| whichis connected by` pipe 52 through valve 53 and check valve 54 tothe upper end of the sidewallof the amalgam ilter press .55. providedfwithan upper piston 56 having a connecting rod l5T mounted therein. which is driven by `la drive mechanism, not shown, and which rconnecting rod isseated, through a packing gland 58, in theiilter head 59.

"The lter head..59is .also provided with| an adjustable cover platev 5B which holds the gland packing inplace.

and the piston` 6lv isprovided with a still smaller or lower piston-.62. A passagewayp extends downwardly through the pistons 56 and tl, and isprovided witha ball check valve 64 at its lowermost end. yThe pistons Si and 82 are slidable in the i interconnected cylinders lB5 and 66 respectively. Bolts'l clamp the plate 58 against the bottom kwall Aof the casing 69 and hold the stack of lterplates- .19 in place. Each lter vplate lll is provided with circular yapertures and when the vplates'are stacked and arranged in the positionv shown inthe drawings. theapertures in `each plate will bealined and willy form the passageways 'l I' whichl are arranged to communicate with the".passagevvays` 'll'. @-By alining the aperturesthey will also .providel a central passageway of the samediameter as the diameter of the walls of The outer end of the passageway 'H'V is internally threaded for the reception `ofapipe l2 having-.a check valve 'I3 and a shutoff valve 14 mounted therein. The pipe 'l2 isalso connected to the T 15 located on the outlet pipe 'lv bel'ow'the concentrator34. The cylinder 65 which is formedin the bottom plate 68, lower lter press head IS and plug tting l'L'isprovided with an outlet pipe i8. .An adjustable pressure reliefvvalve i9 is interposed between the outlet pipe 18 and the cylinder. f In operation'my continuous amalgamating systeml maybe used with or without water in the initial mixingv step. The flow sheet disclosing the operation using Waterin'the initial step is illustrated in Fig. 6 and the operation which does not use water is shown in the'ilolwA sheet'ofFig. 7, the. principal difference The filter press;55 is I The piston 55 is provided withv an integrally formed smaller or central piston 6L -bladesof the centrifugal pump throw the stream of ore and water in a downward direction and intoa vmercury bath. The direction of iiow is illus- `trated by the arrows shown in Fig. 4 of the drawings.

The ore'is `thrown with suilicient force that it breaks through the lm formed on the surface of the mercury so that all particles of precious metals are :forcibly delivered into the mercury within the bath to form amalgams. The field set up by the solenoid located `beneath or surrounding the mercury bath causes a more pronounced absorption of themetals bythe mercury. By heating the mercury the amalgamating action is accelerated and the electrical iield produced by the solenoid at the same time breaks down the colloids which hamper amalgamation. l

All of the ore leaving the blades of the centrifugal pump is forced orvdriven into the mercury'bath, and tends to drive the mercury in the direction of the rotation and motion of the blades in the iront compartment of the bath, even though the blades at no time contact the mercury in the bath, itself. This causes a circulation of the mercury in the bath'and producesa higher of mercury in the outlet end of the bath.

The bailie plate in the mercury bath causes a recirculation through the back compartment to complete a circuit of the mercury stream, and allows it to reenter the iront compartment to repeat its action. The direction of motion is shown in Fig. 5. v

The mercury is maintained in a compact stream bythe novel and particular action caused by this construction that continuously breaks up the overlaying film produced on the surface of the bath and at the same time causes all of the particles of metal carried by the incoming hydraulic stream to be thrown into forceful impingement with the mercury stream. By rapid recirculation of the hydraulic stream through control ofthe material leaving thepump, I am able to cause a rapid, re-

peated forceful impingement of all the metal con-- tents uponand into the same stream of mercury whereby these particles of metal, no matter how iinely divided, are forced by pressure into the mercury stream to very eiectively form the desired amalgams.

The movement of the newly formed amalgams out of the zone of impingement caused by the circulation vof the metal and mercury in the bath, causes a fresh, bright surface to be presented at all points of contact for the finely divided particles and to cause a free field of entry into the mercury stream or bath.

The. amalgam formed in the mercury bath, together with the entrained free mercury, will flow into the amalgam washer through the outlet pipe where it is washed with water which is constantly being circulated in the washer. The amalgam and entraining mercury will then be spread in the washer by the bailes contained therein so that the amalgam and mercury become thoroughly washed by the time they pass entirely through the washer. The free mercury and amalgamwill eventually settle in the bottom ofthe washer and they are drawn fromthe Washer bythe action of the force pump through they outlet pipe', and the mixture is delivered to the top of the concentrator. Any entrained dross that accompanies the amalgam and entrained mercury into the washer will be concentrator acts as a piston forcing part of the free mercury against and through the stack of vfilter discs and the mercury will accumulate .in the central passageway whence it is returned to the mercury bath by suitable piping passing through the heated coil of the inlet piper which is placed in the compartment with the solenoid.

The air pressure supplied to the concentrator will also force the amalgam along the sides of the lter `and downwardly through the outlet pipe, whence it will be forced. into the upper section of the amalgam filter press.

Figure 1 of the drawings shows the piston of the filter press atthe lower end of its stroke, and Fig. 3 shows thevpiston at the upper end of its stroke. As'shown in Fig. 1 with the'piston at the lower end of its stroke, the upper part of the cylinder will be filled with amalgam concentrate, with whatever free mercury that manages to escape from the concentrator. When the piston is raised,` the amalgam concentrate and free mercury will flowathrough the passageway located in the upper and central pistons, and out into the central cylinder. On the down stroke of thepiston, the amalgam concentrate will be under great pressure and will be forced against the stack of filter plates where substantially all 4of the free mercury remaining will beforced through the lter ydiscs and returned by the piping arranged forfthat purpose to thefmercury bath.l The amalgam. concen-` trate is forced to the bottomv of the lower cylinder, and will be compressed by the lower piston against an adjustable relief valve, and the amalgam emitted from `this lter press is sub` stantially a dry amalgam, containing very little if any free mercury. The product is a substantially solid mercury amalgam. l

' Practically all ofthe unamalgamatable materials and entrained dross are ejected by the mercury. By the action of the blades in the centrifugal pump, (the ejected `material is carried along by the water stream and ejected je l through the exhaust outlet of the pump.` A`

very small lm of light dross materialmaybe entrapped when the amalgamiswithdrawn into. the Washer but this will be freed and carried off in the washing step. l j l The function of the amalgam washing. is to remove vany unamalgamated material which may be mixed with or entrained by the mercury withdrawn from the bath.

In the amalgam 'ooncentrator the product as-V sumes ya central stage in that `it is still fluid enough to iiow to the amalgam filter press where it is again subjected to such great pressure against the filters that it assumes a semi-,solid state. In this semistate, however, it' is repeatedly stripped down fro-m the platesby the pistons and packed as solid amalgam. The free `mercury is removed through the iilters as filtrate and returned directly to the mercury` bath. f

The pressure exerted by the downward stroke of the pistons has two actions, first to force all excess mercury through the filter, and second, to scrape down all solid and semi-solidpcon` centrated amalgam that is formed on kthe filter surface into the small cylinder, where 'it is compressed by the lower piston against theA adjustable relief valve or plug, through which itis ejected as substantially dry amalgam.` V,

This is of great utility because the product contains such a small percentage of mercury that the usual retorting capacity is reduced to a minimum, thereby saving fuel and the handling of excess weightof materials required'by the well known methods. p

It is to be understood that some of thedetails set forthy may be alteredvor omitted without departing from the spirit of theinvention as dened by the following claim.

I claim: r

In the `gold extracting art, the methodv of forming a mercury and gold amalgam,A in va mercury bath divided to form a closed channel, which consists in projecting a stream of comminuted gold ore diagonally into the mercury,

the direction of impact being inclined in onlyV one direction with repect to the channel whereby circulation and consequentvmixng of the mercury and ore areinduced. l y o n HARRY I-I. CULMEB.. 

